The present invention relates to an inhalation device for use in the administration of medicament to a patient. The device has a mouthpiece, which is reversibly retractable from a storage position located inside the body of the device to a dispensing position in which the mouthpiece protrudes from the body of the device.
The use of inhalation devices in the administration of medicaments, for example in bronchodilation therapy, is well known. Such devices generally comprise a body or housing within which a medicament container is located. A mouthpiece (or nozzle) is typically provided, wherein xe2x80x98in usexe2x80x99 the mouthpiece communicates with the medicament container to allow passage of medicament from the source to the mouthpiece and thence, to the patient.
In a typical dispensing operation the body of the device is held by the patient and the mouthpiece (or nozzle) of the inhalation device is placed in the mouth (or nose) of the patient. The patient inhales, thereby causing transfer of medicament from the medicament container to the interior of the body of the patient.
When not in use it is desirable, from a hygiene standpoint, that the mouthpiece is provided with some kind of protective cover. The cover desirably acts both to prevent build-up of dirt on the mouthpiece and to prevent ingress of dirt into the body of the device through the mouthpiece, which might then be subject to inhalation by a patient.
It is known to provide the mouthpiece with a protective cap which acts as a protective cover. The cap may either be an entirely separate element or it may be joined to the body of the device in some way. DE-A-3,639,836, for example, describes a device in which the protective cap is mounted on an arm, which is pivotally mounted to the body of the device.
As an alternative to the use of a protective cap, one might envisage a device having a mouthpiece which is reversibly retractable from a storage position in which the mouthpiece is contained within the body of the device to a dispensing position in which the mouthpiece protrudes from the body of the device. In a device of this type the body of the device itself acts as the protective cover when the mouthpiece is in the storage position. The mouthpiece cover is thus an integral part of the inhalation device, avoiding contamination problems of prior art mouthpieces caused by loss of removable mouthpiece covers.
GB-A-2,074,454 describes an inhalation device comprising a tubular body adapted for detachable fitting to an aerosol container. A mouthpiece is provided, which is movable from a storage position to a dispensing position by means of a cap, rotatably mounted on the tubular body, which has biassed actuating means associated therewith. The cap and tubular body are provided with openings of similar dimensions. Manual rotation of the cap to bring the openings into register causes the biassed actuating means to urge the mouthpiece to the dispensing position in which the mouthpiece protrudes from the body of the device. Conversely, rotation of the cap by the user to bring the openings out of register causes the mouthpiece to be moved to the storage position in which the mouthpiece is contained within the body of the device.
The device described in GB-A-2,074,454 requires the use of biassed actuating means (e.g. resilient strip, elastic element), which urge the mouthpiece towards the dispensing position. A disadvantage associated with the use of such biassed actuating means is that they can be prone to mechanical failure (e.g. the overstretched spring or elastic band) or to becoming dislodged within the device (e.g. the xe2x80x98lost springxe2x80x99). Where the action of the device relies on the use of a biassed actuating means, such mechanical failure or dislodgement can lead to non-functioning of the device. In particular, the mouthpiece becomes irretrievable.
The Applicants have now found that a device having a mouthpiece which is reversibly retractable from a storage position to a dispensing position can be constructed without reliance on any biassed actuating means.
According to one aspect of the present invention there is provided an inhalation device for dispensing medicament comprising
a body;
a medicament carrier;
a mouthpiece, reversibly movable from a storage position wherein said mouthpiece is within said body to an in-use position wherein a portion of the mouthpiece protrudes from the body and wherein the mouthpiece is in communication with said medicament carrier to allow passage of medicament therebetween; and
a mouthpiece actuator, movable relative to the body, and coupled to the mouthpiece such that movement of said mouthpiece actuator in a first direction moves the mouthpiece towards said storage position and movement of the mouthpiece actuator in a second direction moves the mouthpiece towards said in-use position
characterised in that the device comprises no biassing means acting on the mouthpiece actuator.
In particular, the device herein comprises no biassing means acting such as to bias the mouthpiece actuator towards either the in-use position or the storage position.
Herein the term xe2x80x98mouthpiecexe2x80x99 is used in a generic sense to mean an element shaped such as to be insertable into the mouth or nose of a patient for inhalation therethrough.
In one preferred aspect, the mouthpiece actuator and mouthpiece are coupled, for example, by a coupling mechanism. In one preferred aspect, the coupling mechanism comprises a rack and pinion mechanism. In another particularly preferred aspect, the coupling mechanism comprises a hinged lever mechanism.
In another preferred aspect, the mouthpiece actuator and mouthpiece are directly coupled. Preferably the mouthpiece actuator is a rotatable turning device directly coupled to the mouthpiece.
In one aspect, the medicament carrier is within the body. In another aspect, the medicament carrier is attachable to the exterior of the body.
Preferably, the mouthpiece is comprised of an elastic material.
Preferably, the mouthpiece is provided with a cover comprised of an elastic material.
Preferably, the inhalation device additionally comprises a curtain arrangement contactable by the mouthpiece on movement of the mouthpiece from the storage to the in-use position. More preferably, the curtain arrangement comprises a plurality of curtains comprised of an elastomeric material.
Preferably, the mouthpiece actuator is provided with a safety trigger mechanism to prevent accidental actuation thereof.
Preferably, at least a portion of the mouthpiece actuator is shaped for ease of grip by the user.
Preferably, at least a portion of the mouthpiece actuator has a friction-enhancing coating.
Preferably, the device is provided with a dose counter, which indicates the number of doses dispensed from or remaining in the container. More preferably, the dose counter comprises an indexing mechanism actuated by a predetermined movement of the medicament container relative to the body.
Preferably the mouthpiece is actuable by a sliding thumb motion.
Preferably, the medicament container is an aerosol or a dry-powder container.
According to another aspect of the present invention, there is provided the use of an inhalation device provided herein for dispensing medicament.